It is well known that contacting steel with water will result in corrosion or rust on the surfaces of the steel. Likewise, aqueous silicone emulsions tend to rust or corrode steel surfaces to which they may be applied or come in contact with. Because of the ability of the silicone emulsion to corrode or rust steel surfaces, they must be used in applications wherein they do not come in contact with steel. If the emulsions are used in applications wherein they come in contact with steel, additives which prohibit the corrosion or rusting of the surface must be added into the silicone emulsion. The practice of adding rust inhibiting additives into silicone emulsions is taught in U.S. Pat. No. 2,894,913 to Sullivan et al. The '913 patent states that rust inhibitors may be added but does not further exemplify what compounds may fall into the class of rust inhibitors.
There are several compounds known in the art as rust inhibitors that may be added into the silicone emulsions. These include sodium benzoate and sodium nitrite. These compounds are typically added into the silicone emulsion at levels of 0.1 to 1% by weight of the total emulsion. It is especially difficult to find rust inhibitors which are useful in emulsions containing quaternary ammonium chloride surfactants.
It is an object of this invention to show silicone emulsion compositions which do not rust or corrode steel surfaces and further do not contain additives for inhibiting rust.
It is further an object of this invention to show the rust inhibiting silicone emulsions which are produced by mechanical emulsification methods comprising cationic surfactants containing an anion whose parent acid has a pK.sub.a of at least 3.
It is further an object of this invention to show the rust inhibiting silicone emulsions which are produced by emulsion polymerization emulsification methods whereby the reactants comprise cationic surfactants containing an anion whose parent acid has a pK.sub.a of 3 or greater, basic catalysts and catalyst neutralizers selected from acids having a pK.sub.a of at least 3.